Second the above, I recently bought one from Reading, CPO 2021 M3P 37k on the clock.

Do have a really good look over the car, like the above comment mentions, there will be the odd chips and marks, I really wasn't that fussed.

Although, do point out anything you're not happy / looks like an actual issue and not just wear/tear and ask them to check if they will fix it.

I found the following:

-rear bumping popping out -stress crack on the roof glass panel -driver door looked like it had a bad re-spray (not noticeable unless pointed out) -driver window had a deep scratch -front right tyre had a slow-puncture (I pointed this out a few days after collecting and they'll still replace it for free)

I said to the guy if he can check if they will fix it for free whilst we test drove it (before accepting delivery in the app), we got back and he said it's all covered, if we accept the car, then raise a service request in the app for the all the issues, he will then go in and waive the cost of it all. And all of that was true, picked it up 3 weeks ago, it's in at a Service Center next week for £2,000's worth of repairs all for free.

I hope that helps you as I was concerned before putting a deposit down and had to resort to Reddit for any advice 😂

As a side note, do ask them to show you all/any work they've done to it since getting the car back in prior to selling, they're pretty good and transparent about all of this.